Pembrolizumab Glioblastoma Trial Reports Median PFS of 10.7 Months

Trial results for pembrolizumab in combination with standard therapy for patients with glioblastoma were posted on ClinicalTrials.gov on 2026-03-25. The Phase 2 study (NCT03197506) reported a median progression-free survival of 10.7 months in Group 2, alongside safety data.

Background

The trial investigated pembrolizumab, an immunotherapy, in combination with standard therapy including chemotherapy such as temozolomide, for patients with glioblastoma. Glioblastoma, gliosarcoma, and supratentorial glioblastoma are aggressive forms of brain cancer.

Trial design

The study (NCT03197506) was a Phase 2 trial that enrolled 52 participants. It investigated pembrolizumab and standard therapy in treating patients with glioblastoma, gliosarcoma, and supratentorial glioblastoma. The interventions included pembrolizumab and temozolomide.

Key results

The trial reported on safety and efficacy measurements. Incidence of Dose Limiting Toxicities (DLTs) was low, with 1 participant in Group 1 Dose Level 1 Cohort 1, 1 participant in Cohort 2, 0 participants in Cohort 3, and 1 participant in Cohort 4. Adverse Events (AEs) occurred in 6 participants in Group 1 and 18 participants in Group 2. The median Time Until Treatment Related Grade 3+ Adverse Event was 6.9 Months for Group 2 (not available for Group 1). For Group 2, key efficacy metrics included a median Overall Survival (OS) at 18 Months observed in 19 participants, a median Time to Progression of 10.7 Months, a median Progression-free Survival of 10.7 Months, and a median Time to Treatment Failure of 8.3 Months.

What this means

The posted trial results provide initial safety and efficacy data for pembrolizumab in combination with standard therapy for patients with glioblastoma. The observed median progression-free survival of 10.7 months and median time to progression of 10.7 months in Group 2 offer insights into the potential clinical activity of this regimen. Safety data, including the incidence of dose-limiting toxicities and adverse events, contributes to understanding the tolerability profile of the combination therapy in this patient population.

Source

The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03197506, titled "Pembrolizumab and Standard Therapy in Treating Patients With Glioblastoma," were posted on 2026-03-25 on clinicaltrials.gov.